There has been conventionally known a technique of acquiring a captured image of the periphery of a vehicle by using an in-vehicle camera and monitoring an object existing outside the vehicle on the basis of the captured image with the purpose of supporting vehicle driving.
For example, Patent Document 1 discloses a technique of calculating the three-dimensional position of an object existing ahead of a vehicle on the basis of a stereo image of the area ahead of the vehicle acquired using two in-vehicle cameras and detecting a white line on the road on which the vehicle is traveling and the position of a sidewall object on the basis of the three-dimensional position information.
In addition, for example, Patent Document 2 describes a technique of detecting stud-type lane marks such as Botts Dots, cat's eye, and the like on the basis of the shape of an object in a captured image acquired by an in-vehicle camera.